Several types of manually propelled watercraft are known in the prior art. U.S. Pat. Nos. 1,640,390; 3,180,306; 3,779,202; and 3,874,319 all disclose manually propelled watercraft having a solid elongated body and a propulsion system consisting of a pair of manually driven propellers located at the front of such body. The rider lies prone on his stomach and propels the craft by turning a crankshaft with his arms which drives the propellers. All of these prior art devices suffer from the disadvantage that the elongated body of the craft must be at least as long as the typical rider. This makes the craft difficult to store and transport. The "surf board" style bodies of these devices lie low in the water. As a result even small waves wash over the craft and its rider. These devices also offer little in the way of comfort to the rider who lies on the hard upper surface of the craft. It is painful for the rider when the craft is buffeted by waves. Another problem of prior manually propelled watercraft is that the arc of rotation of the crankshafts used to propel the craft, extends below the craft's bottom. Thus, in shallow water the rider may strike his hands on rocks or other obstructions resulting in injury.
Inflatable watercraft have also been known for many years. Inflatable "air mattresses" have the advantage that they are comfortable to ride and easy to store in the deflated condition. Such craft have traditionally had the disadvantage that they are unstable and easily overturned by wave action or by relatively small movements of the rider. Inflatable craft have generally not been adopted for manual propulsion due to the difficulties associated with mounting the propulsion mechanism on the inflatable body. U.S. Pat. No. 4,376,420 discloses a leg driven personal watercraft. This craft is designed with a Y-shaped body which helps to overcome some of the instability associated with its inflatable construction. This craft would still have considerable inherent instability however. This leg driven craft could not be adapted to manual propulsion, because the craft could not support the weight of a rider's torso in the propeller area and the water spray generated by the inboard paddle construction would not be acceptable on the rider's face and upper body.
Thus, there exists a need for a manually propelled personal watercraft which is highly stable and which provides comfort and ease of storage.